The lifter angle I never understood. As the engine was built for basic passenger service, it’s not a big deal at all. For racing, now we have problems.
Why they did not correct it from the get to is probably due to the population in modifying there cars and not getting into major surgery to do it and just use the available cams.
Later on when the race blocks did come with the corrected lifter angles, cam prices went into outer space and since a core is around $300, then shipping to you, then shipping to a grinder to have this specialty cam ground to your specs, a thing few of us can do is know exactly what to have ground on the lord, then pay to have it shipped back to you….. dang that’s an expensive camshaft! A price many are not willing to pay for just the cam.
A lot of what they did back on the engine when it was first designed was never thought of a a racing engine because such things were not on the radar or even dream world. U h of the advice of the factory was use the big block to go racing.